gn format: Have format sort sources

tools/gn/token.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TOOLS_GN_TOKEN_H_
 #define TOOLS_GN_TOKEN_H_
 
 #include "base/strings/string_piece.h"
 #include "tools/gn/location.h"
 
@@ skipping 44 matching lines @@
 
     NUM_TYPES
   };
 
   Token();
   Token(const Location& location, Type t, const base::StringPiece& v);
 
   Type type() const { return type_; }
   const base::StringPiece& value() const { return value_; }
   const Location& location() const { return location_; }
+  void set_location(Location location) { location_ = location; }
   LocationRange range() const {
     return LocationRange(
         location_,
         Location(location_.file(),
                  location_.line_number(),
                  location_.char_offset() + static_cast<int>(value_.size()),
                  location_.byte() + static_cast<int>(value_.size())));
   }
 
   // Helper functions for comparing this token to something.
   bool IsIdentifierEqualTo(const char* v) const;
   bool IsStringEqualTo(const char* v) const;
 
  private:
   Type type_;
   base::StringPiece value_;
   Location location_;
 };
 
 #endif  // TOOLS_GN_TOKEN_H_